Focal nodular hyperplasia of the liver

　　The exact etiology of focal nodular hyperplasia of the liver (FNH) is not yet clear. Clinical examinations have found that ovulation inhibitors can cause various changes in liver tissue; there are also cases of FNH occurring during pregnancy and FNH occurring in patients with female Cushing's syndrome, indicating that the occurrence of FNH is related to sex hormone metabolism. However, in literature reports, FNH not only appears in any age and gender, but also in women who do not take birth control pills. Another view suggests that the occurrence of FNH may be related to the reduction of limited blood supply or vascular malformations caused by inflammation, trauma, etc., leading to atrophy of liver cells and compensatory hyperplasia of liver tissue, which is a manifestation of liver focal 'regenerative degeneration.' This view needs further confirmation.

　　Focal nodular hyperplasia of the liver (FNH) rarely presents with complications such as spontaneous rupture or hemorrhage. Malignant transformation generally does not occur. If nodules occur around the porta hepatis, they may cause portal hypertension, while the rest of the liver tissue is normal or atrophic. In the late stage of the disease, liver dysfunction can cause abnormal oil aversion, nausea, vomiting, and other symptoms; digestive dysfunction can lead to decreased appetite; liver cell damage can cause an increase in serum transaminases and other enzymes, while cholinesterase decreases, leading to fatigue, drowsiness, and other symptoms; abnormal bile pigment metabolism can cause jaundice.

　　Approximately 75% of patients with focal nodular hyperplasia of the liver (FNHL) are asymptomatic and are often discovered incidentally during ultrasound or abdominal surgery. Symptomatic patients may present with right upper quadrant pain, discomfort, liver enlargement, or a mass in the right upper quadrant. Physical examination may reveal a hard mass under the right costal margin or in the right upper quadrant, with tenderness, a smooth surface, and movement with respiration. Clinically, based on the patient's good health status, absence of a history of hepatitis or liver cirrhosis, and combined with imaging studies, typical FNHL can be diagnosed by BUS, CT, and MRI. However, there is a need to enhance the recognition of such diseases, especially when the history does not match the results of imaging studies, to prevent misdiagnosis.

　　There are currently no effective preventive measures for focal nodular hyperplasia of the liver (FNH), and early detection and early diagnosis are the key to the prevention and treatment of the disease. However, by paying attention to the following points during the course of the disease, the progression of the disease can be prevented.

　　1. Patients must cooperate well with the doctor's active treatment, rest seriously, and regulate their diet reasonably. They should not drink alcohol or smoke.

　　2. Avoid factors that may worsen liver damage. To protect the damaged liver, unnecessary drugs should be used sparingly or not at all, such as anthelmintics, analgesics, tetracyclines, anesthetics, or drug abuse.

　　3. Pay attention to personal hygiene to prevent reinfection with other diseases. If a new disease occurs, it should be treated actively in the early stage, otherwise it may promote the recurrence of liver disease.

　　5. Avoid heavy physical labor within half a year after recovery and control sexual activity.

　　4. Do not donate blood or inject blood products unless necessary to prevent infection with hepatitis B, C, D, G, and other diseases.

　　Focal nodular hyperplasia of the liver (FNH) usually presents with no specific clinical symptoms, and liver function tests and AFP levels are generally normal. In addition to clinical symptoms, examinations such as ultrasound, CT, MRI, and ECT have limited value in the qualitative diagnosis of FNH, as FNH has a similar tissue density to the liver, lacking contrast, making it difficult to diagnose using the aforementioned methods. Hepatic angiography and colloid 99mTc radionuclide imaging can be helpful, with about 1/3 of patients showing typical findings on hepatic angiography, where the central blood vessels of the mass appear radially in the arterial phase, and fibrous septa are arranged radially in the parenchymal phase, with clear boundaries. The 99mTc radionuclide imaging shows that FNHL, due to the presence of liver macrophages, often presents with normal or increased uptake of colloid 99mTc, while liver adenomas show less uptake. Accurate qualitative diagnosis depends on histological examination, which can be performed by percutaneous liver biopsy guided by ultrasound.

　　The diet of patients with focal nodular hyperplasia of the liver should be diversified, with more consumption of vitamins, low animal fats, easily digestible foods, fresh fruits and vegetables, reduction of common protein intake, more intake of high-quality protein foods, no consumption of stale, deteriorated, or刺激性 things, less smoking, drinking, and foods that are smoked, roasted, pickled, fried, or salty, avoiding smoking and drinking, a mix of coarse and fine grains for staple foods, to ensure a balanced diet.

　　Surgical resection is the effective and first-line treatment for focal nodular hyperplasia (FNHL) of the liver. It is generally believed that FNHL does not develop into cancer. Some people advocate conservative treatment and strict follow-up for asymptomatic patients with a clear diagnosis of FNH. However, it is generally believed that surgery should still be actively adopted for the following reasons:

　　① FNHL is rare, it is difficult to be diagnosed by imaging, and the final diagnosis still requires pathological judgment. There is still some difficulty in differential diagnosis, with a high rate of misdiagnosis. Especially when it is impossible to differentiate from malignant liver tumors in imaging, treatment should be avoided to delay.

　　② Patients who are younger in age or have larger nodules, which may cause rupture and bleeding in daily life.

　　③ Patients with obvious symptoms and heavy mental burden.

　　④ The efficacy of surgery is certain, and there is no recurrence after long-term follow-up after surgery.

　　For patients with surgical contraindications or large masses unsuitable for surgical treatment, hepatic artery embolization can be used to shrink the mass, but it still needs to be observed strictly and followed up regularly.